119° F is equivalent to 48° C ... so if you look at the coding parameters in the Bimmercode app (see pic below)...you are at the high end for LEVEL 3. If you had the Bimmercode app...you could easily lower the temp setting for the seat back...or have someone change it for you to one of the lower settings available. Good luck.
Perhaps level 3 is too high for your personal situation. I only use that level when I'm wearing a heavy coat in very cold temperatures. If I'm wearing less clothing or thinner clothing...then I only use the lowest heat setting...knowing that at some point the comfort level will be too high and I'll have to readjust the level. Using a higher level doesn't warm the seat up any faster.
BTW, I wasn't sure what model to go with...your car info indicates you have an f01 7 series...but you've posted this question on the f10 5 series forum. I used the f01 7 series supported coding parameters from the Bimmercode app.